131 research outputs found

    Wide-cross whole-genome radiation hybrid (WWRH) mapping and identification of cold-responsive genes using oligo-gene microarray analysis in cotton

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    The first part of this research focused on wide-cross whole-genome radiation hybrid (WWRH) mapping of the cotton (Gossypium) genome. Radiation hybrid mapping has been used extensively to map the genomes of human and certain animal species, but not plant species. In lieu of in vitro hybrid cell line technologies for plants, we developed a novel approach for radiation hybrid mapping based on wide-cross in vivo hybridization. Flowers from one species of cotton, either G. hirsutum or G. barbadense, were -irradiated and then used to pollinate the other species. The resulting hybrid plants were assessed as a mapping tool. Two WWRH mapping panels were constructed from 5- and 8-krad -irradiation treatments. Both panels demonstrated that the WWRH mapping method can be used to map the cotton genome, and that this method complements traditional linkage mapping approaches. The second part of this research focused on the identification of cold-responsive genes using spotted oligo-gene microarray analysis. Increased cold-tolerance in cotton would promote early and uniform seedling establishment, expand the growing season, decrease susceptibility to fungal infections and certain diseases, and increase fiber yield and quality. BLAST searches of the cotton database using amino acid sequences of 93 drought/cold-related genes from Arabidopsis and several other plant species led to 806 cotton orthologous cDNAs and expressed sequence tags (ESTs). Eight hundred and six cotton 70-mer oligos were designed and included in an oligo-gene microarray containing 1,536 70-mer oligos, each representing a cDNA or EST from cotton, or one of 121 chloroplast genes or 66 mitochondrial genes from Arabidopsis. Thirty-eight cotton cDNAs and ESTs were identified as cold-responsive genes based on experimental treatment and oligo-gene microarray analysis. Expression was up-regulated for 36 genes and down-regulated for two genes by cold treatment. Results from microarray analysis were tested and confirmed by northern blot analysis for 16 genes. Our data suggest that Arabidopsis orthologous genes can be used to identify homologous cotton genes. The oligo-gene microarray is a valid approach to study transcriptional changes in cotton

    Preparation of Material for Adsorption Ag(I) in the Solution

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    The application of silver in electronics, jewelry, catalytic and other industries often produces a large amount of silver-containing wastewater, which causes serious impact to the surrounding environment and human health, while silver has a certain economic value attached to it. Therefore, how to effectively treat and recover Ag(?) from the silver-containing wastewater is a hot topic of concern at present. In order to seek an efficient and environmentally friendly adsorbent, this paper compared the adsorption efficiency of purified, thermally modified, acid modified and thermally-acid modified Bentonite on silver, selected an economical and reasonable purified clay as a carrier, and then completed the preparation of modified Bentonite as well as the optimization of conditions with sodium silicate as a surfactant and 3-mercaptopropyltrimethoxysilane as a modifier. The experiments showed that under the conditions of sodium silicate dosage of 15% of Bentonite, Bentonite and modifier dosage of 1:1, solution pH of 9, temperature of 45 °C and modification time of 5 h, the synthesized sulfhydryl modified Bentonite has good adsorption performance on Ag(?), and its adsorption capacity can reach 293.7 mg·g-1

    A younger Universe implied by satellite pair correlations from SDSS observations of massive galaxy groups

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    Many of the satellites of galactic-mass systems such as the Miky Way, Andromeda and Centaurus A show evidence of coherent motions to a larger extent than most of the systems predicted by the standard cosmological model. It is an open question if correlations in satellite orbits are present in systems of different masses. Here , we report an analysis of the kinematics of satellite galaxies around massive galaxy groups. Unlike what is seen in Milky Way analogues, we find an excess of diametrically opposed pairs of satellites that have line-of-sight velocity offsets from the central galaxy of the same sign. This corresponds to a 6.0σ\pmb{6.0\sigma} (p\pmb{p}-value $\pmb{=\ 9.9\times10^{-10}})detectionofnon−randomsatellitemotions.Suchexcessispredictedbyup−to−datecosmologicalsimulationsbutthemagnitudeoftheeffectisconsiderablylowerthaninobservations.Theobservationaldataisdiscrepantatthe) detection of non-random satellite motions. Such excess is predicted by up-to-date cosmological simulations but the magnitude of the effect is considerably lower than in observations. The observational data is discrepant at the \pmb{4.1\sigma}and and \pmb{3.6\sigma}$ level with the expectations of the Millennium and the Illustris TNG300 cosmological simulations, potentially indicating that massive galaxy groups assembled later in the real Universe. The detection of velocity correlations of satellite galaxies and tension with theoretical predictions is robust against changes in sample selection. Using the largest sample to date, our findings demonstrate that the motions of satellite galaxies represent a challenge to the current cosmological model.Comment: 28 pages, 9 figures, accepted for publication in Nature Astronom

    Direct conversion of astrocytes into neuronal cells by drug cocktail

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    Direct conversion of astrocytes into neuronal cells by drug cocktail Cell Research advance online publication 2 October 2015; doi:10.1038/cr.2015.120 Dear Editor, Neurological disorder is one of the greatest threats to public health according to the World Health Organization. Because neurons have little or no regenerative capacity, conventional therapies for neurological disorders yielded poor outcomes. While the introduction of exogenous neural stem cells or neurons holds promise, many challenges still need to be tackled, including cell resource, delivery strategy, cell integration and cell maturation. Reprogramming of fibroblasts into induced pluripotent stem cells or directly into desirable neuronal cells by transcription factors (TFs) or small molecules can solve some problems, but other issues remain to be addressed, including safety, conversion efficiency and epigenetic memory [1, 2]. Astrocytes are considered to be the ideal starting candidate cell type for generating new neurons, due to their proximity in lineage distance to neurons and ability to proliferate after brain damage. Many studies have already revealed that astrocytes of the central nervous system can be reprogrammed into induced neuronal cells by virus-mediated overexpression of specific TFs in vitro and in vivo [3-6]. However, application of this virus-mediated direct conversion is still limited due to concerns on clinical safety. We have previously reported direct conversion of somatic cells into neural progenitor cells (NPCs) in vitro by cocktail of small molecules under hypoxia [7]. Here we set out to explore whether astrocytes can be induced into neuronal cells by the chemical cocktail in vitro

    Long-term whole blood DNA preservation by cost-efficient cryosilicification

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    This work was supported by the National Natural Science Foundation of China (21972047 to W.Z., 52003086 to Q.L.), Guangdong Provincial Pearl River Talents Program (2019QN01Y314 to Q.L.), the Program for Guangdong Introducing Innovative and Entrepreneurial Teams (2019ZT08Y318 to W.Z.), Natural Science Foundation of Guangdong Province, China (2021A1515010724 to Q.L.), China Postdoctoral Science Foundation (2020M672625, 2021T140213 to Q.L.), Science and Technology Project of Guangzhou, China (202102020352 to W.Z., 202102020259 to Q.L.), the Fundamental Research Funds for the Central Universities of China. The authors thank the support from the Guangzhou Women and Children’s Medical Center and Laboratory Animal Research Center of the South China University of Technology. S.W. acknowledges funding from the Basque Government Industry Department under the ELKARTEK and HAZITEK programs.Deoxyribonucleic acid (DNA) is the blueprint of life, and cost-effective methods for its long-term storage could have many potential benefits to society. Here we present the method of in situ cryosilicification of whole blood cells, which allows long-term preservation of DNA. Importantly, our straightforward approach is inexpensive, reliable, and yields cryosilicified samples that fulfill the essential criteria for safe, long-term DNA preservation, namely robustness against external stressors, such as radical oxygen species or ultraviolet radiation, and long-term stability in humid conditions at elevated temperatures. Our approach could enable the room temperature storage of genomic information in book-size format for more than one thousand years (thermally equivalent), costing only 0.5 $/person. Additionally, our demonstration of 3D-printed DNA banking artefacts, could potentially allow 'artificial fossilization'.Publisher PDFPeer reviewe

    Metabolic synthetic lethality by targeting NOP56 and mTOR in KRAS-mutant lung cancer.

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    BACKGROUND Oncogenic KRAS mutations are prevalent in human cancers, but effective treatment of KRAS-mutant malignancies remains a major challenge in the clinic. Increasing evidence suggests that aberrant metabolism plays a central role in KRAS-driven oncogenic transformation. The aim of this study is to identify selective metabolic dependency induced by mutant KRAS and to exploit it for the treatment of the disease. METHOD We performed an integrated analysis of RNAi- and CRISPR-based functional genomic datasets (n = 5) to identify novel genes selectively required for KRAS-mutant cancer. We further screened a customized library of chemical inhibitors for candidates that are synthetic lethal with NOP56 depletion. Functional studies were carried out by genetic knockdown using siRNAs and shRNAs, knockout using CRISPR/Cas9, and/or pharmacological inhibition, followed by cell viability and apoptotic assays. Protein expression was determined by Western blot. Metabolic ROS was measured by flow cytometry-based quantification. RESULTS We demonstrated that nucleolar protein 5A (NOP56), a core component of small nucleolar ribonucleoprotein complexes (snoRNPs) with an essential role in ribosome biogenesis, confers a metabolic dependency by regulating ROS homeostasis in KRAS-mutant lung cancer cells and that NOP56 depletion causes synthetic lethal susceptibility to inhibition of mTOR. Mechanistically, cancer cells with reduced NOP56 are subjected to higher levels of ROS and rely on mTOR signaling to balance oxidative stress and survive. We also discovered that IRE1α-mediated unfolded protein response (UPR) regulates this process by activating mTOR through p38 MAPK. Consequently, co-targeting of NOP56 and mTOR profoundly enhances KRAS-mutant tumor cell death in vitro and in vivo. CONCLUSIONS Our findings reveal a previously unrecognized mechanism in which NOP56 and mTOR cooperate to play a homeostatic role in the response to oxidative stress and suggest a new rationale for the treatment of KRAS-mutant cancers

    Energy-flow-reversing dynamics in vortex beams: OAM-independent propagation and enhanced resilience

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    Since their discovery in the 1990s, vortex beams, known for their ability to carry orbital angular momentum (OAM), have found substantial applications in optical manipulation and high-dimensional classical and quantum information communication. However, their inherent diffraction in free space, resulting in OAM-dependent beam expansion, has constrained their utility in spatial mode multiplexing communication, fiber optic transmission, and particle manipulation. These domains necessitate vortex beams with OAM-independent propagation characteristics. Addressing this, we report an approach that employs the energy redistribution mechanism to reverse the radial energy flows of traditional vortex beams, thereby presenting iso-propagation vortex beams (IPVBs) with OAM-independent propagation dynamics. These IPVBs, attributed to their reversed radial energy flows, maintain resilience in diverse environments, from free space to challenging media, including sustaining their form post-damage, retaining consistent intensity in lossy media, and experiencing reduced modal scattering in atmospheric turbulence. Their unique features position IPVBs as promising candidates for applications in imaging, microscopy, optical communication, metrology, quantum information processing, and light-matter interactions. Case studies within optical communication reveal that the IPVB basis potentially unlocks a broader spectrum of data channels, enhancing information capacity over traditional spatial multiplexing techniques

    Synergistic effects of FGFR1 and PLK1 inhibitors target a metabolic liability in KRAS-mutant cancer.

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    KRAS oncoprotein is commonly mutated in human cancer, but effective therapies specifically targeting KRAS-driven tumors remain elusive. Here, we show that combined treatment with fibroblast growth factor receptor 1 (FGFR1) and polo-like kinase 1 (PLK1) inhibitors evoke synergistic cytotoxicity in KRAS-mutant tumor models in vitro and in vivo. Pharmacological and genetic suppression of FGFR1 and PLK1 synergizes to enhance anti-proliferative effects and cell death in KRAS-mutant lung and pancreatic but not colon nor KRAS wild-type cancer cells. Mechanistically, co-targeting FGFR1 and PLK1 upregulates reactive oxygen species (ROS), leading to oxidative stress-activated c-Jun N-terminal kinase (JNK)/p38 pathway and E2F1-induced apoptosis. We further delineate that autophagy protects from PLK1/FGFR1 inhibitor cytotoxicity and that antagonizing the compensation mechanism by clinically approved chloroquine fully realizes the therapeutic potential of PLK1 and FGFR1 targeting therapy, producing potent and durable responses in KRAS-mutant patient-derived xenografts and a genetically engineered mouse model of Kras-induced lung adenocarcinoma. These results suggest a previously unappreciated role for FGFR1 and PLK1 in the surveillance of metabolic stress and demonstrate a synergistic drug combination for treating KRAS-mutant cancer
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